The present invention relates to a centrifugal pump mounting structure which allows easy, sturdy, and reliable mounting of the pump on its bed in several different dispositions or attitudes.
A few different basic structures have conventionally been used in the so-called end suction centrifugal pumps to suspend or mount the pump on a bed or bed plate. These prior art structures are illustrated in FIGS. 1, 2 and 3 of the drawings herein. FIG. 1 illustrates a pump, the body of which is mounted on its bed by bolts so as to make it possible to turn the casing of the pump to different positions allowed by the bolts. This kind of mounting involves some disadvantages, for instance pipe line forces cause distortions and the whole mounting has to be dismounted for service of the bearing part of the pump.
More modern process pumps generally employ the structure illustrated in FIGS. 2A and 2B which eliminates the disadvantages discussed above. A drawback of this FIGS. 2A and B structure is that this kind of a pump mounting can be used to mount a pump on a conventional bed in only one position, in most cases with the pressure outlet opening facing straight upwards, which position is determined by the support legs. This kind of mounting results in problems particularly when high consistency stock is pumped from a stock vessel or when the stock to be pumped must be taken on the same level to another device, e.g. to a beaching tower which is fed from below. In the first mentioned case problems are caused by the stock flow piping which is usually remarkably expanded or enlarged just after the pump in order to avoid unnecessary flow resistance. When the pump is situated by the side of the stock vessel and the pressure opening is directed upwards, the distance between the pressure pipe from the pump and the vessel is so short that the enlargement required in the piping cannot be arranged without a bend in the pressure pipe. As this bend or elbow is by means of a rather narrow pipe, the flow resistance will be quite high. This kind of resistance could be avoided altogether by arranging the pressure opening of the pump facing sidewards in which case the curved surface of the stock vessel would give space for the enlargement of the piping immediately after the pressure opening. In the second case where stock is to be taken on the same level from one device to another the problem is the same since a bend or elbow is needed in the vertical pressure pipe to turn the stock flow to the same level with the subsequent device. This bend causes the same flow loss as the bend in the first case.
FIGS. 3A and 3B illustrate a typical process pump for hot liquids which pump is mounted at the center line of the pump in order to avoid distortions caused by thermal elongation. This kind of a pump presupposes quite an expensive support structure in the bed if sufficient sturdiness is to be achieved.
Further, different positions of the pump require different structures of the bed.
None of the above prior art structures which are commonly used, meets the requirements of a good mounting for a pump; the most important requirements are:
good strength and rigidity in view of the pipe line forces;
that the parts of the pump (bearings, impeller, sealing) which require service must be detachable from the pump without the need to detach the casing from the piping;
that the positions of the pump must be changeable without complex bed structures or necessary changes in the structure of the bed;
that the structure must be inexpensive and readily manufactured.
The centrifugal pump mounting structure of the present invention well meets all these basic requirements. Further, the pump structure of the present invention provides great advantages in standardization of the manufacture of pumps and in reducing the costs of manufacture. Further, one and the same pump can be used for several different purposes and in several different positions or attitudes without beds or special structure.
The centrifugal pump structure of the invention is characterized in that the legs are situated spaced apart at the opposite sides of the pump to the pressure outlet opening and on opposite sides of a longitudinal plane passing through the pump shaft and the pressure outlet opening; that the legs each have first and second planar surfaces extending in different directions for mounting of the pump; and that there is on one side or are on opposite sides of the pressure connection and substantially in the longitudinal plane passing through the shaft of the pump, a bracket or brackets with planar mounting surfaces.